Direct access storage device with a molded actuator motor coil support

Abstract

An actuator for a PCMCIA DASD incorporates a tie bridge for stabilizing the support arms of the actuator while at the same time not increasing the largest radial dimension of the actuator drive motor beyond that of the radial dimension for the exterior of the coil. The tie bridge is disposed above, below, or both above and below the coil of the actuator drive motor. This space otherwise unused is now advantageously utilized, while additionally creating benefits in the design and the operation of the DASD. A crash stop and latch surface are incorporated into the structure of one of the support arms supporting the coil in such a way that the forces encountered by the actuator upon forcible engagement with a rigid structure within the DASD housing are absorbed and thereby reduced to values less than critical failure values.

What is claimed is: 
     
       1. A disk drive (70) for storing and retrieving data relative to the planar surface (74) of a magnetic disk (72), comprising: a magnetic disk mounted for rotation about a first axis that extends normal to said planar surface of said disk;   a carbon fiber reinforced plastic hub (32);   a bearing (20) mounting said hub for rotation about a second axis (22) that is parallel to and spaced from said first axis;   an arm assembly (34,36) extending from a first side of said hub normal to said second axis;   a slider (38) supported by said arm assembly so as to cooperate with said planar surface of said disk;   a magnetically permeable and planar pole piece (12) disposed at a fixed position adjacent to an opposite side of said hub;   said pole piece occupying a third plane that is parallel to said planar surface of said disk;   a planar magnet (18) disposed at a fixed position adjacent to said opposite side of said hub;   said magnet occupying a fourth plane that is parallel to and spaced from said third plane;   said spacing of said pole piece and said magnet defining a magnetic gap having a thickness measured parallel to said second axis;   an outer arcuate surface (26) formed on said magnet;   said arcuate outer surface of said magnet being formed as a first radius about said second axis;   a pair of arcuately spaced, elongated, and equal length carbon fiber reinforced plastic coil support arms (30) formed integrally with said hub and radially extending from said opposite side of said hub;   each of said coil support arms having a distal end (30a) that extends beyond said arcuate outer surface of said magnet;   a carbon reinforced plastic tie bridge (40) integrally formed with and extending between said distal ends of said coil support arms;   said tie bridge having a top portion, and having a bottom portion that is located in said fourth plane;   said bottom portion of said tie bridge having an arcuate inner surface (27) that is radially spaced from said arcuate outer surface of said magnet and is formed as a second radius about said second axis;   said second radius being greater than said first radius;   a planar, open center, wire coil (16) having a first coil leg (46) integrally formed with one of said coil support arms, having a second coil leg (44) integrally formed with the other of said coil support arms, having a third coil leg (42) integrally formed with said top portion of said tie bridge, and having a fourth coil leg integrally formed with said hub;   said coil support arms and said first and second coil legs being arcuately movable within said magnetic gap and about said second axis;   said coil support arms and said first and second coil legs having a thickness measured parallel to said second axis that is less than said thickness of said magnetic gap;   said tie bridge and said third coil leg being located outside of said magnetic gap and having a thickness measured parallel said second axis that is greater than said thickness of said magnetic gap;   a flexible circuit board (62) disposed on said hub;   two electrical leads (78) extending from said fourth coil leg and connected to said flexible circuit board;   a flexible cable (60) connected to said flexible circuit board;   a flexible, U-shaped, carbon fiber reinforced plastic crash stop (50) integrally formed with said distal end of one of said coil support arms;   said U-shaped crash stop forming a shock absorbing member for engagement with a stop surface that is disposed within said disk drive; and   said U-shaped crash stop having a latching surface (54) for engagement with a hub latching member that is disposed within said disk drive.